Preparation of 2-phenyl-3-pyridol from 2-benzoylfuran



Patented Mar. 16, 1954 PREPARATION OF 2-PHENYL-3-PYRIDOL FROM 2.-B,ENZOYLFURAN Andrew P. Dunlop,

Riverside, BL, and Samuel Swadesh, Mill Valley, Calif., assignors to The Quaker Oats Company, Chicago, 111., a corporation of New Jersey No Drawing. Original a 1950, Serial 2,636,882,

pplication August 11,v

No. 178,998, now Patent N0. dated April 28, 1953. Divided and this application April 12, 1952, Serial No.

The portion of the term to April 28, 1970,

6 Claims.

This invention relates to the preparation of 2-pheny1-3-pyridol from 2-benzoy1furan being a division of our copending application Serial No. 178,998, filed August 11, 1950 and now United States Patent No. 2,636,882, issued April 28, 1953.

One object of the present invention is to provide an emcient process for the preparation of 2-pheny1-3-pyridol. Another object is to provide a process for the preparation of 2-phenyl- B-pyridol in a direct manner which can be easily carried out using relatively inexpensive equipment. A very important object is to provide an improved process for producing 2-phenyl-3- pyridol by reacting 2-benzoylfuran with ammonia. Other objects and advantages of the present invention will become apparent to those skilled in the art as the invention is more fully described.

Broadly stated, the present invention provides an improved process for the production of 2-phenyl-3-pyridol which comprises heating 2-benzoylfuran with ammonia in the presence of a solvent which is a good ionic medium, preferably water or an alcohol or a mixture of the two at elevated temperatures. Suitable temperatures may vary from about 100 to 200 0., however, we generally prefer to operate within a temperature range of 120 to 180 C. It should be understood, however, that higher or lower temperatures may be used with a resultant increase or decrease in the reaction rate in accordance with the general law of chemical reactions.

The proportion of the reactants namely, 2-benzoylfuran and ammonia used in our process may be varied over a wide range. Theoretically, in our process one mole of 2-benzoylfuran reacts with one mole of ammonia in accordance with the following equation:

In practice, however, we prefer to employ an excess of ammonia.

The product of our invention has been characterized as a 3-pyridol by means of C, H, and N analysis, determination of neutral equivalent, by formation ofthe picrate. derivative and by of the patent subsequent has been disclaimed the fact that it produces a red color with FeCla, which is characteristic of a phenolic compound.

In order to disclose the nature of the present invention still more clearly, the following illustrative example will be given in which parts by weight bear the same relation to parts by volume as do grams to cubic centimeters.

EXAMPLE Preparation of 2-phenyl-3-pyridol To 25 parts by weight of 2-benzoylfuran were added 196 and 300 parts by volume of 28% ammonium hydroxide and methanol respectively. After heating the mixture for about 21 hours at a temperature of 150 to 160 C. in an autoclave, it was treated with parts by weight of activated carbon in two equal increments and then concentrated at reduced pressure on a steam bath until crystal formation was observed, at the same time a small amount of dark oily liquid separated. The concentrated solution was cooled, a small amount of alcohol added to redissolve the oily liquid and then filtered. 16.1 parts by weight of 2-phenyl-3-pyridol M. P. 202.4 to 203 C. was obtained which represented a per cent yield of theory. The picrate derivative after recrystallizing from alcohol had a melting point of 201.0 to 201.4 C.

Analysis 0 H N ggggg,

CnHoONZ Theory 77.19 5.26 8.19 171. Found 77.48 5.21 8.12

a purificationagent and to-facilitate the recoveryof the final product, its use may be dispensed with if desired.

We claim:

1. A process for the production of z-phenyl- 3-pyridol which comprises reacting Z-benzoylfuran with ammonia at a temperature of 100-200 C. in the presence of a solvent selected from the class consisting of water, alcohol, and solutions of the same.

2. A process for the production of 2-phenyl-3- pyridol which comprises reacting z-benzoylfuran with ammonia at a temperature of l20-l80 c. in the presence of a solvent selected from the class consisting of water, alcohol, and solutions of the same.

3. A process for the production of Z-phenyl- 3-pyridol which comprises reacting 2-benzoyl furan with ammonia at a temperature of l00-200 C. in the presence of alcohol as a solvent.

4. A process for the production of 2-phenyl- 3-pyridol which comprises reacting 2-benzoylfuran with ammonia at a temperature of 100-200 C. in the presence of water as a solvent.

5. A process for the productionof z-phenyl- 3-pyridol which comprises reacting 2-benzoylfuran with ammonia at a temperature of 120-l80 C. in the presence of alcohol as a solvent.

6. A process for the production of 2-phenyl- 3-pyridol which comprises reacting Z-benzoylfuran with ammonia at a temperature of 120-180 C. in the presence of water as a solvent.

ANDREW P. DUNLOP. SAMUEL SWADESH.

Name Date Dunlop et al. Apr. 28, 1953 Number 

1. A PROCESS FOR THE PRODUCTION OF 2-PHENYL3-PYRIDOL WHICH COMPRISES REACTING 2-BENZOYL FURAN WITH AMMONIA AT A TEMPERATURE OF 100-200* C. IN THE PRESENCE OF A SOLVENT SELECTED FROM THE ELASS CONSISTING OF WATER, ALCOHOL, AND SOLUTIONS OF THE SAME. 